Various designs for multiple-pane window blinds have been developed. In such assemblies, window blinds are placed between two panes of glass and surrounded by a frame. Between the panes of glass there may be a mechanism for tilting the blinds, as well as a mechanism for raising and lowering the blinds. These mechanisms are well known in the art and may include cords, pulleys, or rotating bars.
For instance, a cord may be attached to an operator at one end and attached at the other end to a set of blinds through a series of pulleys. The operator may be moved up and down by an adjuster located on the exterior of the glass. The adjuster and the operator may be magnetically coupled to each other so that movement in one leads to movement in other. As the operator is moved up and down, the cord will move in response, raising or lowering the blinds. In addition, an operator may be attached to a mechanism, such as a rotating bar, to tilt the blinds between an open to a closed position. These operators can be separate, or a single operator and adjuster combination may perform both functions.
In such blind assemblies, the adjuster may be attached a number of different ways: it may ride along the exterior of a pane of glass, being held in place through only its magnetic attraction to the operator; it may attach to a track formed integrally with the frame; and it may attach to a track which is then secured directly to the exterior of a pane of glass. Each of these methods, however, has drawbacks.
When attached to the operator via the magnetic attraction only, the adjuster will move along the surface of the glass, which may lead to scratching and marking. Also, the force exerted by a user may overcome the magnetic force between the adjuster and the operator, causing them to dislodge.
When the track is integrally formed with the frame, a flexibility problem may arise. Depending on the size of the window and the specific blind adjustment mechanisms, the location of the operator with respect to the edge of the frame may vary. To accommodate for these differences a new frame must be designed and made for each application. Where a track is attached directly to a pane of glass, repeated use may weaken the bond between the two. This may eventually cause the track to fall off and the adjuster to dislodge from the operator. Thus a need exists for an improved track for an adjustable blind assembly.